Open-hearth furnace



(No Model.)

J. PURVES.

OPEN HEARTH FURNACE.

Patented Oct. 30,1894

UNITED STATES PATENT-l Games.

JAMES PURYES,-OF MUNHQLL, PENNSYLVANIA.

OPEN-HEART-H FURNACE.

SPECIFICATION formingpart of Letters Patent no. 528,510, dated October 30, 1894. I

- .Appllcation'filed September-22,1992. snammueen. (Remodel-l To all whom it may concern.- i Y Be it known that I, JAMES PURVES, of M unhall, in the county of Allegheny and State of Pennsylvania, have invented a new and use ful Improvement in Open-Hearth Furnaces, of, which the following is a full, clear, and exact description, reference being bad to the accompanying drawings, forming partof this specification; in which-- a furnace constructed in accordance with my.

- invention.

Figure 1 isa vertical longitudinal section of Fig. 2 isa horizontal section on the line Il -II. one of the tapping-holes. Fig. 4. is a vertical section onthe line IV-IV of Fig. 3. Fig.5 is a partial front elevation of one of the working holes. Fig. 6 is a vertical section onthe' line VI-VI of Fig. 5, showing the reversible door.

'Llk6 symbols of reference indicate like parts in each figure. I

Owing to the high temperatures employed in open-hearth melting furnaces, great difliculty has been experienced with the refractory materials generally used, in that they will not withstand the heat without melting. It is proposed, in the present invention, to

construct such a form of furnace aswill en-,

able more refractory material to be used in all parts of the melting chambers and-ports, and also to make the hearth and roof (the parts most liable to accident) interchangeable, thus rendering the furnace less liable to destruction by overheating, more susceptible of repair while still hot, and the skill and care hitherto indispensable, to a certain extent annecessary.

The proposed furnace consists of a hOllZOlltal, cylindrical vessel, having three doors on each side and openings at each end to admit gas and air, or to withdraw the products of combustion, and carried on suitable rollers and capable of being turned on its longitudinal axis by a rack and toothed wheel, or other Fig. 3 is a front elevation of situate at diametrically opposite points, and

preferably constructed as shown in Figs. '3 and 4 each having an annular casting 5, sur- 5 rounding the hole in the shell and fitted with a movable door 6. 7 is a spout which projects laterally from, the shell at each of the tap-holes.

The spOut Tis-made detachable from the shell of the furnace, so that it may be removed and shifted in position from the upper to the; lower side of the tap-hole, and vice versa, thus enabling the necessary changes to be made when the furnace is inverted as hereinafter described. I

The holes 4 are used mainly as orifices through which metal and slag may no poured and for affording access to the'hearthfor purposes of repair. There are also other opening's 8, situate near the ends of the furnace. and in the same plane with the doors 4, They are used for charging the furnace with the stock to be melted therein. The holes 8 are also providedwith door-frames 8 secured 7 to the furnace-shell and both above and below the openings 8 are journal supports or bearings 18, adapted to support a roller 19, acting also as asill-plate, which is removable and reversible in position so that it may be properly adjusted when the furnace is inverted. The opening is providedwith a door 20, which is used when the furnace is in, either position. Theinversionot thefurnace also inverts the doors, which (top and bottom 8 being similar) are in no way affected i the change; beyond that the lifting chains will now be hooked in what was the bottom staple before inversion, t'. e., if the doors be kept over the charging holes while the furnace is- 9 being turned, which may easily be done by keying up the doors in their places before inversion. llowevcigasthesupportsfrom which these doors are hung will be entirely independent of the furnace shell (the rollers being removed) the furnace maybe inverted while the doors are allowed to hang just where they were. This saves unhooking and hook- I log up again.

The furnace shell is supported on rollers 9,- uphcld by suitable circular frames, and bearing against bands or plates 10, which surround, the furnace shell. T he furnace is. adapted-to lie-turned on these supports by tutes the hearth (after withdrawal of the metal and slag) may he brought uppermost and made to serve the function of a roof, the part constituting the roof beingthen brought into -position to serve as thehearth.

The ends of the parts 3 of the furnaceshell communicate directly with chambers formed by hollow shells 13, whose shape is thatoi. a. truncated cone, through which gas and air enter the furnace at one end and from which the products of combustion are dis charged at the other end alternately. The chamber 13 is supported independently of the furnace, and in practice I prefer to make the shell of one of the parts 3 or 13 overlap the other, so as to cover the intermediate joint while permitting the free rotation of the fur nacc-shell. it

14, 15, are gas and air fines at each end of the furnace, which enter the chambers 13 and connect the same with regenerators. Not shown. The flues of the chamber 13 and the interior of the furnace shell are aliprovided with a refractory lining 16 and in lining the chamber 13, the refractory material may he I to burn or to he in the position usually 'turning the furnace through rammed or bricked around suitable cores, preferably hollow, before the attachment of the aiuflue at the end. thus lined, the ha'cloplate is put on, the air flue attached, and the cores, which are eini') ply supports used in construction, allowed melt out as the furnace heats up. The gas and airlines leading to and from these ports may be constructed as shown, or of any other form found most convenient, al though that shown is believed to he the best.

' After a suitable lining has been in sorted i n.

the furnace, either by bricking or ramming, I preferoblyprooeed as follows:---The hearth or that portion of the furnacewhich happens occupied by the hearth, is covered with material of a less refractory nature than the hearth itself, and which will flux (but not to an injurious extent) with the lining itself. A; quantity of slag will thus collect upon the tem. There should be sufficient of this slag to cover all the interior of the melting-chum her, and this can he eitectcd by temporarily closing one or both of the tap-hole doors, and half a revolution, so as to glaze the entire surface. On the portions of the furnace next the parts which the slug will notcovcr, it must b splashed and 'more of the flux aforeunem tionedshould be thrown upon them through the doors when tho furnace is turned down. Thefaoe of thelining thus havingocen glazed and set, and sufiicihnt heat having been, obtained, the furnace is ready. to charge and operate in the usual manner.

After the ports are" hearth, m

,its operation renders itellicicntinthe menufacture oi steel. i r

The method heretofore usually employed in putting bottoms into opeuhearlh furnaces is also applicable to'this furnace. It is to put a brick lining in, just thick enough to protect the shell, then to get a melting heat on the furnace, and then begin adding the refractory stuff of which the hearth is to be composed in small quantities at a time all over, setting such thin layers with sufficient neat, then adding anotherlaycr, and so on.

. until the desired thicirness of hearth is obrained.

1n the event of repairs being wanted in that portion of the furnace which is being used as a root, pro term, the furnace, after I being tapped or poured, can be turned down, the repairs made through the doors, set and glazed over, and the roof returned to its former position. in the event of that portion of the furnace which is being used 10m 6cm.) as a hearth becoming full of steel,

or what is gencrally'known as dirty) and unsafe to melt; upon or defective in any other way, the hearth may he used cs a. roof, and the portion which has been in service as a roof turned down, anda practically new and clean bottom obtained on which to'begin operations. Should this portion, while acting as a root, have become thin, it is easily thickened. up in the usual manner through the doors. l

The manner oi usoof the furnace will be understood by those skilled in the art. The

cud-fines 1i, l5,heing connected with regeuorator-chambers, and there being suitable gas and air supplies, as usual in regenera; tive furnace" construction the gas and air-are caused to enter one end of the furnace, burn therein, and then pass out; the other end to the regenerators which they serve to heat, the course of gas and aimed the products ofcombustion being revcrsecl fromtime to time in the usual manner. 'The charge having been introduced through the doors 8, ismelted on the furnacehearth, and after the melting operation, the furnace may be tipped on its longitudinal axis to discharge the cinder and molten metal through one of thetapholes. When desired, the furnace between successive melts, may be completely inverted so an to interchange the positiou of thehearth and root. In such case, the same openings will serve when the furnace isin either position, all thatu's necessar being to reverse the position of the detachable spout.

The advantages oi my invention will be appreciated by those skilled in the 'art. B reason of the reversible construction of the, furnace, and the highly refractory material rendered available by such construction, the apparatus is very durable, and the ease of Without limiting myself with prcciseness to theconstruction ahovedescribed and shown in the drawings, which may be modified without variance from-my invention, what];

I is

oieim, and desire to secure by Letters Patent, 1s-- 1. An invertible open-hearth furnace, having opposite lateral doors, supports on which it can be turned throughout at least a semirevolution, a detachable spout, out} an invertible door; substantially as and" for the purposes described.

2. An invertible open-hea2sth furnace, hzwing a lateral door, a. door-frame having at the top and bottom thereof journal-supports for a. roller, and a removable roller adapted to be jom'naled in said supports; substantially as described.

In testimony whereof I hage hereunto set 15 my hand thisBd dav of September, A. D.

I JAMES PURvEs. .Vitnessesi W. B. Conwm,

JAMES K. BAKEWELL, 

